Biotechnology explores the metabolic properties of living organisms for the production of valuable products of a very different structural and organizational level. Plant serves as an important source of primary and secondary metabolites used in pharmacy, biotechnology, and food technology. Plant biotechnology has gained importance in the recent past for augmenting the quality and quantity of agricultural, horticultural, ornamental plants, and in manipulating the plants for improved agronomic performance. Plant tissue culture is the most popular technique of plant biotechnology, which has diverse applications in the various fields. To understand the basic facts related with plant in vitro studies it is worth acknowledging historical principles of plant tissue culture science, which takes its roots from ground-breaking research like discovery of cells followed by the propounding of cell theory. This chapter covers various major historical achievements such as the concept of cellular totipotency, which was inherent in cell theory and was further elaborated by Haberlandt in 1902. This historical account created the scope and development for plant tissue culture science such as research and production of transgenic plants and their products, which could be of use to mankind as food, medicine, and life-saving drugs.